Presentation 2017-10-27
A Revised Version of "Games with a Single Pile of Stones and Number Theoretic Problems"
Yoshihiro Tsukamura, Yoshihide Igarashi, Takaaki Fujita, Yuta Urabe, Koichi Yamazaki,
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Abstract(in Japanese) (See Japanese page)
Abstract(in English) The game MSP(m) discussed in this paper, is played alternately by two players, removing at least one stone and at most $m$ stones from the single pile at each turn. Each player is prohibited from removing the same number of stones as the number of stones removed by the opponent at the immediately previous turn. A player who makes the pile empty wins the game. Furthermore, when a player cannot remove any number of stones due to the prohibition rule, the opponent becomes the winner. This game is denoted by MSP(m). In our previous report [Games with a Single Pile of Stones and Number Theoretic Problems, COMP2016-17 pp.17-24], we formulated the initial numbers of stones, called unsafe number of stones, at the pile such that the second player of MSP(m) is promised to become the winner. However, we discovered that there were some serious errors in the previous report. In this paper, we remove the errors in the previous one, and add some new results. We categorize MSP(m)s into types $1, 2, 3, ..., k, k + 1, ...$ according to certain properties of $m$'s. Then for each type of MSP(m)'s we investigate the periodicity of unsafe numbers. For vast majority of MSP(m)'s, from the periodicity we can efficiently decide which player is promised to become the winner of the game with a given initial number of stones.
Keyword(in Japanese) (See Japanese page)
Keyword(in English) a pile of stones / algorithms / games / number theory / prohibition / strategies
Paper # COMP2017-22
Date of Issue 2017-10-20 (COMP)

Conference Information
Committee COMP
Conference Date 2017/10/27(1days)
Place (in Japanese) (See Japanese page)
Place (in English)
Topics (in Japanese) (See Japanese page)
Topics (in English)
Chair Hiro Ito(Univ. of Electro-Comm.)
Vice Chair Yushi Uno(Osaka Pref. Univ.)
Secretary Yushi Uno(Seikei Univ.)
Assistant

Paper Information
Registration To Technical Committee on Theoretical Foundations of Computing
Language JPN
Title (in Japanese) (See Japanese page)
Sub Title (in Japanese) (See Japanese page)
Title (in English) A Revised Version of "Games with a Single Pile of Stones and Number Theoretic Problems"
Sub Title (in English)
Keyword(1) a pile of stones
Keyword(2) algorithms
Keyword(3) games
Keyword(4) number theory
Keyword(5) prohibition
Keyword(6) strategies
1st Author's Name Yoshihiro Tsukamura
1st Author's Affiliation former Sony Corporation(former Sony)
2nd Author's Name Yoshihide Igarashi
2nd Author's Affiliation Gunma University(Gunma Univ.)
3rd Author's Name Takaaki Fujita
3rd Author's Affiliation Gunma University(Gunma Univ.)
4th Author's Name Yuta Urabe
4th Author's Affiliation Gunma University(Gunma Univ.)
5th Author's Name Koichi Yamazaki
5th Author's Affiliation Gunma University(Gunma Univ.)
Date 2017-10-27
Paper # COMP2017-22
Volume (vol) vol.117
Number (no) COMP-269
Page pp.pp.13-20(COMP),
#Pages 8
Date of Issue 2017-10-20 (COMP)